I usually tell parents that I can add them to my waiting list and will contact them when a spot opens. If I have a spot open then I email them saying the spot is open on ___ day and if they are willing to pay ahead of time to let me know and we can set up a meeting, if they aren't willing to pay then they will be put back on the waiting list. If I know now that I have a spot available for January then I require a deposit and nothing more. I agree, I just don't think they really understand how it all works and that most times we don't get a lot of notice when a family is leaving.